To evaluate the role of the omohyoid muscle anatomic variants as a possible reversible cause of internal jugular vein extrinsic compression.We describe a chronic cerebro-spinal venous insufficiency patient, who presented a omohyoid muscle entrapment of the internal jugular vein, confirmed by both magnetic resonance venography and ultrasound investigation. A omohyoid muscle surgical transection together with a patch angioplasty was performed.The surgical procedure led to both IJV flow restoration and neurological improvement.The omohyoid muscle compression on the internal jugular vein seems to be a possible cause of venous obstruction, but several anatomical and patho-physiological aspects need further investigations. Such picture might cause balloon venous angioplasty inefficacy and needs to be preoperatively considered.